Design, Synthesis, and Evaluation of Novel and Selective G-protein Coupled Receptor 120 (GPR120) Spirocyclic Agonists.

Type 2 diabetes mellitus (T2DM) is an ever increasing worldwide epidemic, and the identification of safe and effective insulin sensitizers, absent of weight gain, has been a long-standing goal of diabetes research. G-protein coupled receptor 120 (GPR120) has recently emerged as a potential therapeutic target for treating T2DM. Natural occurring, and more recently, synthetic agonists have been associated with insulin sensitizing, anti-inflammatory, and fat metabolism effects. Herein we describe the design, synthesis, and evaluation of a novel spirocyclic GPR120 agonist series, which culminated in the discovery of potent and selective agonist 14. Furthermore, compound 14 was evaluated in vivo and demonstrated acute glucose lowering in an oral glucose tolerance test (oGTT), as well as improvements in homeostatic measurement assessment of insulin resistance (HOMA-IR; a surrogate marker for insulin sensitization) and an increase in glucose infusion rate (GIR) during a hyperinsulinemic euglycemic clamp in diet-induced obese (DIO) mice.

Discovery of Chromane Propionic Acid Analogues as Selective Agonists of GPR120 with in Vivo Activity in Rodents.

GPR120 (FFAR4) is a fatty acid sensing G protein coupled receptor (GPCR) that has been identified as a target for possible treatment of type 2 diabetes. A selective activator of GPR120 containing a chromane scaffold has been designed, synthesized, and evaluated in vivo. Results of these efforts suggest that chromane propionic acid 18 is a suitable tool molecule for further animal studies. Compound 18 is selective over the closely related target GPR40 (FFAR1), has a clean off-target profile, demonstrates suitable pharmacokinetic properties, and has been evaluated in wild-type/knockout GPR120 mouse oGTT studies.

Design and Synthesis of P2-P4 Macrocycles Containing a Unique Spirocyclic Proline: A New Class of HCV NS3/4A Inhibitors.

A new class of hepatitis C NS3/4A inhibitors was identified by introducing a novel spirocyclic proline-P2 surrogate onto the P2-P4 macrocyclic core of MK-5172 (grazoprevir). The potency profile of new analogues showed excellent pan-genotypic activity for most compounds. The potency evaluation included the most difficult genotype 3a (EC50 values ≤10 nM) and other key genotype 1b mutants. Molecular modeling was used to design new target compounds and rationalize our results. A synthetic approach based on the Julia-Kocienski olefination and macrolactamization to assemble the P2-P4 macrocyclic core containing the novel spirocyclic proline-P2 moiety is presented as well.

Discovery of MK-8831, A Novel Spiro-Proline Macrocycle as a Pan-Genotypic HCV-NS3/4a Protease Inhibitor.

We have been focused on identifying a structurally different next generation inhibitor to MK-5172 (our Ns3/4a protease inhibitor currently under regulatory review), which would achieve superior pangenotypic activity with acceptable safety and pharmacokinetic profile. These efforts have led to the discovery of a novel class of HCV NS3/4a protease inhibitors containing a unique spirocyclic-proline structural motif. The design strategy involved a molecular-modeling based approach, and the optimization efforts on the series to obtain pan-genotypic coverage with good exposures on oral dosing. One of the key elements in this effort was the spirocyclization of the P2 quinoline group, which rigidified and constrained the binding conformation to provide a novel core. A second focus of the team was also to improve the activity against genotype 3a and the key mutant variants of genotype 1b. The rational application of structural chemistry with molecular modeling guided the design and optimization of the structure-activity relationships have resulted in the identification of the clinical candidate MK-8831 with excellent pan-genotypic activity and safety profile.

Novel Quinoline-Based P2-P4 Macrocyclic Derivatives As Pan-Genotypic HCV NS3/4a Protease Inhibitors.

We have previously reported the discovery of our P2-P4 macrocyclic HCV NS3/4a protease inhibitor MK-5172, which in combination with the NS5a inhibitor MK-8742 recently received a breakthrough therapy designation from the US FDA for treatment of chronic HCV infection. Our goal for the next generation NS3/4a inhibitor was to achieve pan-genotypic activity while retaining the pharmacokinetic profile of MK-5172. One of the areas for follow-up investigation involved replacement of the quinoxaline moiety in MK-5172 with a quinoline and studying the effect of substitution at 4-position of the quinoline. The rationale for this effort was based on molecular modeling, which indicated that such modifications would improve interactions with the S2 subsite, in particular with D79. We wish to report herein the discovery of highly potent inhibitors with pan-genotypic activity and an improved profile over MK-5172, especially against gt-3a and A156 mutants.

GPR119 agonists for the potential treatment of type 2 diabetes and related metabolic disorders.

Type 2 diabetes (T2D) has reached epidemic proportions, and there is an unmet medical need for orally effective agents that regulate glucose homeostasis. GPR119, a class-A (rhodopsin-like) G protein-coupled receptor expressed primarily in the pancreas and gastrointestinal tract, has attracted considerable interest as a T2D drug target in recent years. The activation of GPR119 increases the intracellular accumulation of cAMP, leading to enhanced glucose-dependent insulin secretion from pancreatic ß-cells and increased release of the gut peptides GLP-1 (glucagon-like peptide 1), GIP (glucose-dependent insulinotropic peptide) and PYY (polypeptide YY). Oral administration of small molecule GPR119 agonists has been shown to improve glucose tolerance in both rodents and humans. This review summarizes the research leading to the identification of GPR119 as a potential drug target for T2D and related metabolic disorders, and provides an overview of the recent progress made in the discovery of orally active GPR119 agonists.

Recent progress in the discovery of adenosine A(2A) receptor antagonists for the treatment of Parkinson's disease.

Antagonism of the adenosine A2A receptor has emerged as a promising non-dopaminergic approach for the potential treatment of Parkinson's disease (PD). Several pharmaceutical and academic institutions have ongoing research programs in this area, and orally efficacious A2A receptor antagonists have been advanced into clinical development. Traditionally, antagonists of the A2A receptor are classified as xanthine and non-xanthine derivatives. This review provides a detailed summary of the recent SAR development that has led to the discovery of promising non-xanthine-based A2A receptor antagonists. The current clinical status and the potential utility of A2A receptor antagonists in indications other than PD are also discussed.

Azabicyclic sulfonamides as potent 11beta-HSD1 inhibitors.

Inhibition of 11beta-HSD1 has demonstrated potential in the treatment of various components of metabolic syndrome. We wish to report herein the discovery of novel azabicyclic sulfonamide based 11beta-HSD1 inhibitors. Highly potent compounds exhibiting inhibitory activities at both human and mouse 11beta-HSD1 were identified. Several compounds demonstrated significant in vivo activity in the mouse cortisone challenge assay.

GPR119 agonists: a promising new approach for the treatment of type 2 diabetes and related metabolic disorders.

Type 2 diabetes (T2D) and associated obesity have reached epidemic proportions, and there is an increasing need for orally effective agents that regulate glucose homeostasis with a concurrent reduction in body weight. GPR119, a class-A (rhodopsin-like) G protein-coupled receptor, expressed primarily in the human pancreas and gastrointestinal tract, has attracted considerable interest as a T2D drug target in the last three to five years. The activation of GPR119 increases the intracellular accumulation of cAMP, leading to enhanced glucose-dependent insulin secretion and increased levels of the incretin hormones GLP-1 (glucagon-like peptide 1) and GIP (glucose-dependent insulinotropic peptide). In rodent models, orally available GPR119-specific agonists have been shown to attenuate blood glucose levels with a simultaneous body weight loss. This review summarizes the research leading to the identification of GPR119 as a potential drug target for T2D and related metabolic disorders. In addition, an overview of the recent progress made in the discovery of orally active GPR119 agonists is provided.

Design, synthesis, and evaluation of fused heterocyclic analogs of SCH 58261 as adenosine A2A receptor antagonists.

SCH 58261 is a reported adenosine A(2A) receptor antagonist which is active in rat in vivo models of Parkinson's Disease upon ip administration. However, it has poor selectivity versus the A(1) receptor and does not demonstrate oral activity. Quinoline analogs have improved upon the selectivity and pharmacokinetics of SCH 58261, but were difficult to handle due to poor aqueous solubility. We report the design and synthesis of fused heterocyclic analogs of SCH 58261 with aqueous solubility as well as improved A(2A) receptor binding selectivity and pharmacokinetic properties. In particular, the tetrahydronaphthyridine 4s has excellent A(2A) receptor in vitro binding affinity and selectivity, is active orally in a rat in vivo model of Parkinson's Disease, and has aqueous solubility of 100 microM at physiological pH.

Biaryl and heteroaryl derivatives of SCH 58261 as potent and selective adenosine A2A receptor antagonists.

SCH 58261 is a reported adenosine A(2A) receptor antagonist, which is active in rat in vivo models of Parkinson's Disease upon ip administration. However, it has poor selectivity versus the A(1) receptor and does not demonstrate oral activity. We report the design and synthesis of biaryl and heteroaryl analogs of SCH 58261 which improve the A(2A) receptor binding selectivity as well as the pharmacokinetic properties of SCH 58261. In particular, the quinoline 25 has excellent A(2A) receptor in vitro binding affinity and selectivity, sustained rat plasma levels upon oral dosing, and is active orally in a rat behavioral assay.

Total synthesis of (-)-himgaline.

The first total synthesis of (-)-himgaline and a highly enantioselective synthesis of its congener (-)-GB 13 are described. Decarboxylative aza-Michael reaction of the hexacyclic lactone precursor under acidic conditions, followed by basic workup, yielded (-)-GB 13 in 80% yield. Cyclization of (-)-GB 13 to oxohimgaline under acidic conditions, followed by internally coordinated sodium triacetoxyborohydride reduction, gave (-)-himgaline as the exclusive product.